1. Field of the Invention
The present invention relates generally to a full thickness resection device. More specifically, the invention provides a control handle for a full thickness resection device.
2. Description of the Related Art
Full thickness resection devices are known. Resection devices are capable of removing a lesion from the patient""s body by stapling and cutting the lesion site. Since it is desirable to perform the resection procedure endoscopically through a naturally occurring body orifice, the resection device may include a flexible shaft extending from the operating end, or distal end, of the device, which is inserted into the patient""s body, to the control end, or proximal end, of the device, which remains outside of the patient""s body. The control end includes a control handle which is used to control the cutting and stapling apparatuses of the device.
Because the resection device includes a flexible shaft, a portion of the apparatus that controls the cutting and stapling apparatus, e.g., that portion of the device that extends from the control handle to the distal end of the device through the flexible shaft, may also be formed of a flexible material. This flexible portion may be a flexible drive shaft that is used to transmit an actuating force from the control handle to the operating, or distal, end of the device. For example, the flexible drive shaft could be rotated in a first direction to actuate the stapling apparatus and rotated in a second direction, which is opposite to the first direction, to actuate the cutting apparatus. In such an embodiment, the drive shaft could be coupled to the stapling apparatus at its distal end and cause the staples to be fired from the stapling apparatus as the drive shaft is rotated in a clockwise direction. At completion of its clockwise rotation, the distal end of the flexible drive shaft could couple with the cutting apparatus and could cause the targeted tissue to be cut as the drive shaft is rotated in a counter-clockwise direction.
However, problems could be encountered with an embodiment of a device as described above. Because the drive shaft that couples the control handle of the device to the distal end of the device is flexible, as the drive shaft is rotated in the clockwise direction, the drive shaft will not only be rotated by the rotation force but the shaft will most likely store torsional energy in it as well. When the force that caused the drive shaft to rotate in the clockwise direction is removed from the drive shaft, the drive shaft will tend to uncontrollably rotate in the counter-clockwise direction due to the uncontrolled release of the torsional energy that was stored in the drive shaft. This could have undesirable consequences since the counter-clockwise rotation of the drive shaft causes cutting of the targeted tissue. Uncontrolled release of the torsional energy stored in the drive shaft could result in complications in the cutting procedure.
Therefore, it would be desirable to provide an improved apparatus and method for a control handle of a full thickness resection device that could more positively control the actuation of the operating end of the resection device.
A control handle for a full thickness resection device is provided. In an embodiment for the control handle of the present invention, the control handle includes a body and a staple firing assembly coupled to the body. The staple firing assembly includes a rotatable staple firing ring, a worm gear assembly rotatably engaged with the staple firing ring, and a flexible drive shaft coupled to the worm gear assembly.
In an embodiment for a method of the present invention, a method for actuating a full thickness resection device is provided. The method includes the steps of rotating a staple firing ring in a first direction and actuating a worm gear assembly in a first operative mode in response to the rotation of the staple firing ring in the first direction, the worm gear assembly is coupled to the staple firing ring. A flexible drive shaft is rotated in the first direction, the flexible drive shaft being coupled to the worm gear assembly, and torsional energy is stored in the flexible drive shaft during rotation of the flexible drive shaft in the first direction. The worm gear assembly is actuated in a second operative mode and a release rate of the stored torsional energy in the flexible drive shaft is controlled by the worm gear assembly. The flexible drive shaft is rotated in a second direction.